Octopuses can squeeze through just about any opening, and they're very real. As for how Snare-oh's powers actually work (such as defying gravity by unraveling himself) is a mystery. I doubt even the writers have given it any thought. We're just supposed to accept it as true without questioning (suspension of disbelief or something like that).
i do agree with you that snare-oh's physiology dose defy gravity the wiki also says that when ben first transformed he had trouble figuring out how to control his powers it also could mean that when he transformed he dident have the nessesary moterskills needed to operate this body. also just a thought if he managed to unwrap himself into a form that was not his normal humanode form he would probably not know how to return to humanode form. (just a thought)